I have Raspberry PI 3 (model B) and particle electron (2G) devices. Is it possible to create a connection between these two? I was thinking if Raspberry PI performs sort of controller device and send signals to electron for tracking purposes.

There’s a library names “EasyTransferSerial” that might be useful for your application. I have a situation in which I need to connect to a device over a LAN, but I want to upload the data to the cloud over cellular. I may end up using a Photon for the LAN interface and have it use EasyTransferSerial to get the data to an Electron to be pushed to the cloud service. I’ve tested the library and it works very well…and it’s easy to use!